exxonmobil topped the list followed by apple, google, berkshire and walmart. last year, three chinese companies were in the top five and for the first time in three years, no company in the world is worth $400 billion. >>> gas prices continue to slip across the country and here in the bay area. analysts say they could be lower by the memorial holiday weekend. san francisco averages $4.06. around the rest of the bay area, it's down about 6 cents a gallon. experts say we could be saying 20 cents less by the end of next month. >>> paper or plastic? that's something you won't be hearing much longer in many cities and counties in california. pam cook is in the newsroom with more. >> it's earth day today. to coincide, many cities are joining the effort to reduce, refuse and recycle. redwood city and menlo park, are not allowed to hand out plastic bags and required to charge you 10 cents for a i aer -- paper bag. we asked some people. most are in favor. >> i think it's fabulous. >> tell me why. >> i think any time we can help the earth and recycle bags and go to the